Home-field advantage at the Summer Olympics
This weekend, Brazil had its biggest triumph as the host of the Summer Olympics. In front of a sold-out Maracana Stadium in Rio, a penalty kick off the foot of Neymar netted the country’s first-ever gold medal in men’s soccer. The crowd — having already urged on the Brazilians for 120 gruelling minutes — erupted when they saw the decisive shot hit its mark. I mean, they went nuts. It might have been the loudest moment at the entire Olympics.
It wasn’t just the beautiful game that had the Brazilian fans fired up at the Olympics, though. There were raucous crowds at the late-night beach volleyball matches, too. The less sandy but equally exciting indoor volleyball matches were also a huge hit. Really, all the Brazilian athletes — gymnasts, swimmers, sprinters — were buoyed by the high spirits of their countrymen.
So, the question is: Did all the support make any difference? Is there such thing as a home-field advantage at the Summer Olympics?
The history of host countries in the top 5
You probably remember how well Great Britain performed at the London Olympics in 2012 (29 gold, 17 silver, and 19 bronze medals), right? Before that, China had some super-intimidating drumming during their Beijing opening ceremony in 2008 and some equally impressive athletic performances during the subsequent Games (51 gold, 21 silver, and 28 bronze medals). Both of these countries finished Top-5 in the Olympic medal count as hosts. But, were these results out of the norm for China and Great Britain or pretty much as expected? And have other previous hosts made their way into the Top 5 of the medal count, too?
To make comparisons between historical performances, we’ll look at the proportion of total medals won by each country (according to Sports-Reference), weighting each proportion so that gold medals (x3) count for more than silver (x2) or bronze (x1). For example, China’s 51 gold medals from 2008 accounted for 17 percent of all the gold medals at those Olympics, which they collected along with 7 percent of the silver medals, and 8 percent of the bronze medals. The weighted average of China’s three medal proportions represents a total medal score of 12 percent {score = (17×3 + 7×2 + 8×1) / 6 = 12}. That mark was the best in 2008, even though the U.S. won more total medals.
Based on that scoring system, here’s a look at the five-highest medal scores from each Summer Olympic Games since 1952. The flags of the host countries are shown in color, so that you can trace their ranks through the years. An “H” in the lower-righthand corner of a flag represents a summer spent as the host country.
Top 5 medal scores at the Summer Olympics, 1952-2016.
Focusing first on the host countries, there have been a lot of historically great performances turned in by the home teams. Australia finished outside of the Top 5 in 1952 (No. 10), but jumped all the way up to third place when they hosted in Melbourne during the summer of 1956. Likewise, Italy was able to entertain the fans in Rome by improving to fourth-best in the world in 1960. Four years later, with the Games in Tokyo, Japan made the jump to fourth, after finishing in the eighth spot during the previous Summer Olympics. West Germany was sixth in 1968 and they climbed up to fourth in 1972 when they brought the Games to Munich. South Korea came out of nowhere in 1988 to finish fifth in the medal score while playing host in Seoul. Finally, at the 2000 Sydney Games, Australia boomeranged back into the Top 5 for the first time since 1960.
Aside from the strong performances of the host nations, the other thing that stands out in the plot above is the dominance of the U.S. and the Soviet Union (subsequently, Russia) over the years. So let’s take a quick moment to make a few notes about the USA-USSR Olympic rivalry.
The Olympic arms race
From 1952 to 2004, the U.S. and the Soviet Union (subsequently, Russia) finished in first and second place in all but one of the Summer Games in which both countries competed. There were two other instances — in 1980 with the Olympics in Moscow and in 1984 with the Olympics in Los Angeles — when the U.S. and the Soviet Union traded boycotts. During these two Olympics, the remaining superpower won a disproportionate amount of medals. When the Olympics were in Moscow, the Soviet Union collected an astounding 34 percent of the medals (weighted by value) with the Americans watching from their couches. When the Olympics were in L.A., and the Soviets were at home, the U.S. won 30 percent of the medals. Other countries experienced similar medal bumps during these summers of weakened Olympic competition.
Medal scores for the U.S. and Soviet Union at the Summer Olympics, 1952-2016
Since hosting the Atlanta Olympics in 1996, the USA has maintained a lead over Russia in the medal score. USA-USA! However, the Americans’ apparent advantage is actually a little misleading. If, in addition to Russia’s hardware, you consider the medals won by all of the other countries that were formerly part of the Soviet Union (Armenia, Azerbaijan, Belarus, Estonia, Georgia, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Tajikistan, Turkmenistan,Ukraine, Uzbekistan), you’d find that the former Soviets have been winning this whole time. Even this year, the once-Soviet Union held a slim lead over the U.S. (13.4 percent vs. 13.3 percent), despite the lackluster Russian performance (5.9 percent).
This is all just to show that the U.S. and the Soviet Union are special cases historically due to their extreme dominance at the Olympics. Moreover, the Games of 1980 and 1984 should be treated as outliers, since they were unbalanced competitive affairs. As such, I’m going to ignore these two summers in my home-field advantage calculations below.
Visualizing home-field advantage at the Summer Olympics
To test for a home-field advantage, we’re going to compare each host country’s performance to its baseline Olympic performance, where we define “baseline” as the average medal score from six Olympics: the three Olympics before and the three Olympics after the host summer.
Change in medal score during Summer as host country compared to baseline, 1952-2016
The median changes from baseline are shown with the red line above. The typical improvement over baseline medal score was +2.1 percentage points while hosting. That’s a pretty substantial improvement; the equivalent of roughly 13 extra gold medals based on the current size of the Olympics. Generally, the highest score of each country’s 24-year period was seen during the summer as the host. Two exceptions were the U.S. during the 1996 Olympics (USA tallied slightly better scores in 1988 and 1992) and Great Britain during the 2012 Olympics (the Brits just had a slightly better score in Rio). Interestingly, Great Britain was not the only country who maintained an improvement over baseline four years after hosting; there was a median medal score improvement over baseline of 1.0 percentage points, for all of the countries during the first Olympics after hosting.
For more details on each country’s performance we can view the same information as a table:
China had the biggest improvement in medal score of any host since 1952 (+4.3 percentage points over baseline) and Canada had the lowest (+0.4). This summer, Brazil posted the second-smallest improvement over baseline with its 12th-place effort of 7 gold medals, 6 silvers, and 6 bronzes (+0.7 percentage points). Countries like Mexico with low medal-score baselines found it easy to crush their previous standards (651 percent relative improvement in medal score), whereas the already uber-successful U.S. had little room for improvement (10 percent relative increase in medal score). Still, all-in-all every host country improved over its baseline Olympic performance, typically improving the medal score by about 67 percent relative to baseline.
Home-field advantages
So, aside from the straightforward, “it’s nice to have fans cheering for you” rationale, what might be causing the observed improvement in Olympic performance for host countries?
I can think of a lot of possibilities:
Comfort level: Host athletes know the “lay of the land”. They know the language, the culture. They know against which gas station wall one might safely pee and which ones are protected by armed security guards with video cameras.
Proximity: This might not seem like a legitimate concern in the interconnected modern world, but it might have been an important factor in the 1950s when world travel probably wasn’t feasible for every amateur athlete. It still is important for the purposes of adjusting to time zones, jet lag, that kinda thing. Moreover, local athletes can expect more support from their families and friends.
Immunity: This is only partially a bad joke about the Zika virus, it’s also a serious consideration. This summer, there was the Chinese gymnast who couldn’t do any of her routines because she wasn’t feeling well and the 17-year-old American track athlete who couldn’t run because she had a cold. I empathize. I get sick every time I get on a plane. I would hate to have to travel internationally the week before I was competing in the Olympics.
Honest, but biased judging: This is interrelated to the home-crowd effect. Imagine if a gymnastic judge hears outrageous applause for every move the home team pulls off and derisive Bronx cheers every time a foreign competitor falters, he might end up with a biased opinion of the performances he saw and his scorecard might subconsciously reflect the prevailing sentiments of the crowd.
Judging shenanigans: Above and beyond honest, but biased judging; there might also be just straight-up dishonest judging. For example, in 1968, one of Mexico’s four boxing medals came as the result of a disputed disqualification in an otherwise lopsided gold-medal bout in Mexico City. Is it possible that the referee was unduly influenced by a local citizen with a special interest in the outcome? Perhaps.
Civic pride of athletes: On one level, it’s hard to believe effort level could be a major concern at the Olympic Games; isn’t everyone already trying their hardest? But, clearly, in some instances, the allure of playing in one’s home country does make a big difference. It certainly did for Neymar. He decided to join his mostly 23-and-under Brazilian teammates for a chance to win a gold medal in his home country, whereas other soccer players of his superstar caliber opted not to make the trip.
Funding for training: Countries know that they will host the Olympics seven years in advance of the opening ceremony. That’s ample time to bolster training programs to produce athletes that will be primed for Olympic competition on their home soil.
That last point helps to explain two elements of the information we got from the plots above. First, the medal score improvements — for countries like Great Britain — that have lingered four extra years after the host summer and, second, the relatively modest increase in medal score improvement for Brazil this summer.
It makes sense that a national investment in athletic training would have a residual benefit in Olympic performance beyond the host summer, as the same athletes could return for subsequent Olympics. On the other hand, when a country — like Brazil — experiences economic hardship just as it’s preparing to host the Olympics, it places limitations on the financial investment that can be made in athletic training. In Brazil’s case, the lack of cash on hand seems to have precluded the type of big-time home-field advantage that has been enjoyed by some previous hosts.
Even if the Brazilians didn’t make an exceptionally large medal haul in Rio, they got the one medal that they prized the most, and for that they can always be proud.